Question

In a transistor circuit, the base current changes from $30$$\mu A$ to $90$$\mu A$. If the current gain of the transistor is $30$, the change in the collector current is

• A. $4mA$
• B. $2mA$
• C. $3.6mA$
• D. $1.8mA$

Answer 1

Answer: (D)

$1.8mA$

Given:
$\Delta I_b=(90-30)\mu A=60\mu A$
$\beta =30$
For transistors current gain is
$\beta =\frac{\Delta I_c}{\Delta I_b}$

$\Delta I_c=\beta \Delta I_b$
$\Delta I_c=30\times 60$
$\Delta I_c=1800\mu A$
$\Delta I_c=1.8mA$